Effects Of Plant Growth Substances On The Growth Of Potato Test-tube Seedling And The Induction Of Microtuber

In this study,two new varieties of purple and pink potato were used as experimental material and the technology of plant tissue culture was adopted.To explore effects of single and multiple factors of plant growth substances on the growth of new potato test tube seedlings and microtubers induction,the optimum medium formula and the culture condition of stem tip culture,multiplication,plantlets rooting and microtubers induction were studied by changing the concentration of plant growth substances(plant hormones and plant growth retardants).The result showed that:The effect of plant hormones on test tube seeding of purple and pink potato IBA and NAA promoted root growth of purple and pink potato plantlets,and IBA was better than NAA.When the concentration of IBA was 1.0 mg·L-1,the growth of plantlets root in vitro was significantly better than the other treatments.It was not beneficial to the root growth when the concentration of NAA was more than 0.5mg·L·1 Adding 2,4-D(0.5-2.0 mg·L-1)to MS medium,the plant height increased,stem became slender,and root was not extremely developed,ivory-white and massive callus produced.0.5mg·L-1 TDZ(or O.5mg·L·1 ZT)promoted adventitious bud formation and these were beneficial to buds multiplication.When 6-BA was used exclusively,there was no adventitious bud and it was also unfavorable for the growth of new varieties test tube seeding.In conclusion,MS+IBA 1.0 mg ·L-1+6-BA 1.0 mg·L-1 and MS+NAA 0.5 mg·L-1+6-BA 0.2 mg·L-1 were the best mediums for growth that the leaves of purple and pink potato plantlets expanded,the leaf color deepened,and the plantlets grew well.The effect of plant growth retardants(PP333,CCC and Pix)on test tube seeding of purple and pink potato Adding a certain amount of PP333 was suitable for the growth of purple potato plantlets,the concentration range was 0.020 to 0.025 mg·L-1,and the pink potato was 0.020 mg·L-1.CCC was used that the suitable concentration of potato test tube seeding was 0.06mg·L-1.However,the effect and physiological responses on the growth of plantlets were different.When the plant growth retardant was Pix,the purple potato plantlet was suitable for 200mg·L-1,and the pink potato was 1OOmg·L-1.Three kinds of growth retardants were favorable for the test tube seeding of purple and pink potato.The plantlets were robust and the antioxidant enzyme activities were enhanced.The sequence was PP333>CCC>Pix that single retardant improved seedlings quality.The effect of sucrose concentration on test tube seeding of purple and pink potato Purple potato was more adaptable than pink potato.The optimum medium for purple potato was MS+8%sucrose,and the pink potato was MS+6%.When PP333 was used on the culture medium,MS+ PP333 0.02 mg-L-1+4%sucrose was the optimum medium formula.This medium not only reduces the amount of sucrose,but also conducive to the regulation of osmotic pressure.The effect of culture condition on microtubers induction The optimum culture condition for microtuber induction was the temperature(20±2)?,light intensity 12?13 ?mol·m-2·s-1 and illumination time 14d after darkness.By changing the sucrose concentration to induce microtuber,the purple potato was suitable for 10%sucrose,and the pink potato was 8%sucrose that has a better effect.Microtubers can be induced by the different concentration hormones.The best medium for microtuber induction of purple potato was MS+6-BA 3.0 mg·L-14-NAA 0.1 mg·L-1+6%sucrose,and pink potato was MS+6-BA 1.0 mg·L-1+NAA 0.3 mg·L-1+6%sucrose.These conclusions were acquired based on the analysis of tuberization rate,tuber number and tuber quality.Three kinds of growth retardants about PP333,CCC and Pix can improve the quality of microtuber.The suitable concentrations of purple potato in accordance with the order were 0.03 mg·L-1,0.3 mg·L-1,125 mg·L-1,and the sequence was CCC?Pix ?PP333 that single retardant improved microtuber quality.The pink potato in accordance with the order were 0.05 mg·L-1,0.3 mg·L-1,250 mg·L-1,and the sequence was PP333 ?CCC ? Pix.The optimum medium for microtuber induction of two new potatoes was MS+PP333 0.01 mg·L-1+6-BA 0.5 mg·L-1+NAA 2.0 mg·L-1+ 6%sucrose by mixing PP333,6-BA and NAA together.